WO2021147839A1

WO2021147839A1 - Pull-back syringe having shielding needle eccentric baffle

Info

Publication number: WO2021147839A1
Application number: PCT/CN2021/072626
Authority: WO
Inventors: 张洪杰
Original assignee: 贝普医疗科技有限公司
Priority date: 2020-01-21
Filing date: 2021-01-19
Publication date: 2021-07-29
Also published as: CN111012976A

Abstract

Provided is a pull-back syringe having a shielding needle eccentric baffle (2), the syringe comprising a barrel (1), a core rod (3), a piston (4), a needle hub (5), an elastic support catch (6), a needle tube (7), and the eccentric baffle (2), wherein the inside of the barrel neck of the front end of the barrel (1) is divided into a barrel neck front cavity (102) and a barrel neck back cavity (103) by means of an inner partition plate (101), the eccentric baffle (2) is mounted in the barrel neck front cavity (102), the eccentric baffle (2) is provided with an eccentric hole (201) and multiple blind holes (202), and two or more support points (203, 204, 205) are provided at the outer contour of the eccentric baffle (2); the needle hub (5) is mounted in the barrel neck back cavity (103); the inner wall of the rear portion of the barrel (1) is provided with an annular stop step (106) protruding in the circumferential direction, the outer wall of the front portion of the core rod (3) is provided with a baffle (303) and an elastic barb (304) which are arranged one in front of the other, and the baffle (303) and the elastic barb (304) cooperate with the annular stop step (106) of the barrel (1); and the needle tip of the needle tube (7) passes through the eccentric hole (201) of the eccentric baffle (2) and a needle through hole (107) at the front end of the barrel (1), and is then exposed. The syringe has a compact overall structure, and has a simple self-destruction operation, thereby improving the convenience and safety of the product.

Description

Pull-back syringe with shielding needle eccentric stopper

Technical field

The invention belongs to the technical field of syringes, and in particular relates to a pull-back syringe with an eccentric blocking piece of a shielding needle.

Background technique

The existing retractable syringes mostly use a needle tube retraction mechanism to drive the needle tube to retract into the sleeve to achieve self-destruction, but the needle tip of the retracted needle tube may extend out of the sleeve again, which poses a safety hazard. At the same time, it is necessary to design a needle tube retracting mechanism that is easier to self-destruct operation, so as to improve the convenience and reliability of the retractable syringe product.

Summary of the invention

In view of the above-mentioned problems, the present invention provides a pull-back syringe with an eccentric blocking piece of the shielding needle.

The object of the present invention can be achieved by the following technical solutions: a pull-back syringe with a shielding needle eccentric stopper, including a syringe, a core rod, a piston, a needle seat, an elastic support clip, a needle tube, and the needle The neck of the barrel front end is provided with an inner partition with a central opening. The inner partition divides the inner cavity of the barrel neck of the barrel into a front cavity of the barrel neck and a rear cavity of the barrel neck. The front cavity of the barrel neck and the front end of the barrel The needle through hole is connected, the needle seat is installed in the back cavity of the barrel neck; the rear inner wall of the needle barrel is provided with an annular stop step protruding in the circumferential direction, and the front outer wall of the core rod is provided with a front-to-rear arrangement The baffle and elastic barbs of, the baffle and the elastic barbs are matched with the annular stop step of the needle cylinder;

It also includes an eccentric baffle which is installed in the front cavity of the barrel neck of the barrel. The eccentric baffle is arranged along the radial plane and is axially limited by the internal structure of the front cavity of the barrel neck and the inner baffle. The number of the baffle is more than one, the eccentric baffle is provided with an eccentric hole, the rear end of the eccentric baffle is provided with a plurality of blind holes arranged on the periphery of the eccentric hole in the circumferential direction, and the outer contour of the eccentric baffle is provided with two The above fulcrum; the rear end of the needle tube is fixed on the needle seat, and the needle tip at the front end of the needle tube passes through the eccentric hole of the eccentric baffle and the needle through hole of the needle tube is exposed;

When the core rod pulls back the needle tip of the needle tube and exits the eccentric hole of the eccentric baffle, the eccentric baffle that loses the support of the needle tube will move freely along the radial surface in the front cavity of the neck of the needle tube until it reaches a balanced state. The lower eccentric baffle keeps balance through contact with the inner wall of the front cavity of the barrel neck of the barrel through the fulcrum on the outer contour, the solid surface of the eccentric baffle blocks the needle through hole of the barrel, and the blind hole on the side of the eccentric hole avoids the needle tip of the needle to enter In the eccentric hole;

When the elastic barb of the pulled-back core rod crosses the annular stop step of the needle cylinder, the annular stop step of the needle cylinder is caught between the baffle piece of the core rod and the elastic barb to restrict the axial movement of the core rod.

Further, the inner wall of the back cavity of the barrel neck of the needle cylinder is provided with a protruding tooth sleeve at the front, and the middle outer wall of the needle seat is provided with a tooth hub matched with the tooth sleeve of the needle cylinder.

Further, the inner wall of the back cavity of the barrel neck of the syringe barrel is provided with an annular stop groove recessed in the circumferential direction at the rear, and the rear part of the elastic support clip is in the shape of a disc, and it stops with the ring of the syringe barrel. The slots are matched.

Further, the outer wall of the front end of the core rod is provided with an inverted buckle, the front part of the elastic support clip is installed in the cavity of the rear part of the needle seat by a snap fit, and the front part of the elastic support clip is in a hollow cylindrical shape. And the inner wall of the front part is provided with a buckle matched with the inverted buckle of the core rod.

Further, the outer wall of the rear part of the needle seat is provided with a sealing ring installation groove recessed in the circumferential direction, and a sealing ring is installed in the sealing ring installation groove.

Further, the front outer wall of the core rod is provided with an elastic support body, and the elastic support body is matched with the rear end surface and the inner wall of the piston.

Further, the outer wall of the rear part of the core rod is provided with a safety sheet, and the safety sheet is matched with the rear end surface and the inner wall of the needle cylinder.

Further, the eccentric hole of the eccentric baffle is provided with rounded corners along the edge.

Compared with the prior art, the present invention has the following beneficial effects: an eccentric stopper is installed in the neck of the needle cylinder, and when the needle tip of the needle tube is pulled back to drive the needle tube to completely exit the eccentric hole of the eccentric stopper, the eccentric stopper blocks the needle The needle through hole of the barrel effectively prevents the needle tube that can still move axially through the eccentric baffle. The rear inner wall of the needle cylinder is provided with an annular stop step, and the front outer wall of the core rod is provided with a matching stopper and an elastic barb. When the elastic barb of the pulled back core rod crosses the annular stop step of the needle cylinder , The annular stop step of the needle cylinder is clamped between the stop piece of the core rod and the elastic barb, which restricts the axial movement of the core rod, thereby leaving the elastic support clamp, needle seat, needle tube, and piston in the needle cylinder. The overall structure is compact, and the self-destruction operation is simple, which improves the convenience and safety of the product.

Description of the drawings

Fig. 1 is a schematic structural diagram of an embodiment in a state of being used or filled with injection liquid.

Fig. 2 is a schematic diagram of the structure of an eccentric baffle in an embodiment.

Fig. 3 is a cross-sectional view of an eccentric stopper in an embodiment.

Fig. 4 is a schematic diagram of a posture of the single-piece eccentric baffle in a balanced state in an embodiment.

Fig. 5 is a schematic diagram of another posture of the single-piece eccentric baffle in a balanced state in an embodiment.

Fig. 6 is a schematic diagram of an embodiment in which the injection solution is fed to the bottom.

FIG. 7 is a schematic structural diagram of an embodiment in a preliminary state of self-destruction.

Fig. 8 is a schematic structural diagram of an embodiment in a completely self-destructed state.

Fig. 9 is a schematic diagram of a posture of the three eccentric baffles in a balanced state in an embodiment.

Fig. 10 is a schematic diagram of another posture of the three eccentric baffles in a balanced state in an embodiment.

The part numbers in the figure are as follows:

1 syringe

101 internal partition

102 tube neck anterior cavity

103 tube neck posterior cavity

104 tooth sleeve

105 ring stop groove

106 ring stop step

107 pin through hole

2 eccentric baffle

201 eccentric hole

202 blind hole

203 pivot a

204 pivot b

205 pivot c

3-core rod

301 Undercut

302 elastic support

303 block

304 elastic barb

305 insurance film

4 pistons

5-pin socket

501 gear hub

6 Elastic support card

601 snap

7 needle tube

8 Sealing ring.

Detailed ways

The specific embodiments of the present invention will be described in detail below in conjunction with the accompanying drawings, so that those skilled in the art can more clearly understand how to practice the present invention. Although the present invention has been described in conjunction with its preferred specific embodiments, these embodiments are only illustrations, and do not limit the scope of the present invention.

Refer to Figure 1, a pull-back syringe with a shielding needle eccentric stopper, including a syringe barrel 1, an eccentric stopper 2, a core rod 3, a piston 4, a needle seat 5, an elastic support clip 6, a needle tube 7, and a seal Circle 8.

The neck of the front end of the syringe 1 is provided with an inner partition 101 with a central opening. The inner partition 101 divides the inner cavity of the neck of the syringe 1 into a front cavity of the neck 102 and a back cavity of the neck 103. The front cavity 102 of the cylinder neck communicates with the needle through hole 107 at the front end of the cylinder 1, the inner wall of the back cavity 103 of the cylinder neck is provided with a protruding tooth sleeve 104 at the front, and the inner wall of the back cavity 103 of the cylinder neck is provided with a flange at the back. The annular stop groove 105 is concave in the circumferential direction, and the rear inner wall of the needle cylinder 1 is provided with an annular stop step 106 protruding in the circumferential direction.

The eccentric baffle 2 is installed in the front cavity 102 of the neck of the syringe 1, and the eccentric baffle 2 is arranged along the radial surface and is axially restricted by the internal structure of the front cavity 102 and the inner partition 101. , The number of the eccentric baffle 2 is more than one; referring to Figures 2 and 3, the eccentric baffle 2 is provided with a penetrating eccentric hole 201, the eccentric hole 201 is provided with rounded corners along the edge, and the back of the eccentric baffle 2 The end surface is provided with a plurality of blind holes 202 evenly distributed on the peripheral side of the eccentric hole 201 along the circumferential direction, and the outer contour of the eccentric baffle 2 is provided with more than two fulcrums.

Wherein, the outer contour shape, the number of fulcrums, and the distribution positions of the fulcrums of the eccentric baffle 2 are variable. In this embodiment, referring to Figure 2, the outer contour of the eccentric baffle 2 is provided with 6 fulcrums, which are respectively 2 fulcrums a203, 2 fulcrums b204, and 2 fulcrums c205. The eccentric baffle 2 is in the barrel of the syringe 1. The anterior neck cavity 102 has two postures in a balanced state, see FIG. 4 and FIG. 5.

The core rod 3 is installed in the syringe 1, the front end outer wall of the core rod 3 is provided with an inverted buckle 301, and the front outer wall of the core rod 3 is provided with an elastic support body 302, a baffle 303 and an elastic inverted Hook 304, the elastic support body 302 is matched with the rear end surface and the inner wall of the piston 4, the baffle 303 and the elastic barb 304 are matched with the annular stop step 106 of the barrel 1, and the rear outer wall of the core rod 3 A safety piece 305 is provided, and the safety piece 305 is matched with the rear end surface and the inner wall of the syringe 1.

The piston 4 is sleeved on the front part of the core rod 3.

The needle holder 5 is installed in the back cavity 103 of the neck of the needle cylinder 1, the front part of the needle holder 5 is provided with a needle fixing hole penetrating along the axis, and the middle outer wall of the needle holder 5 is provided with a tooth hub 501. 501 is guided and matched with the tooth sleeve 104 of the needle cylinder 1, a cavity with a rear opening is provided in the rear part of the needle holder 5, and a sealing ring installation groove recessed in the circumferential direction is provided on the outer wall of the rear part of the needle holder 5.

The front part of the elastic support clip 6 is installed in the cavity at the rear of the needle base 5 by a snap fit, the front part of the elastic support clip 6 is a hollow cylindrical shape and the inner wall of the front part is provided with a front end of the core rod 3. With the buckle 601 matched with the inverted buckle 301, the rear part of the elastic support clip 6 is arranged outside the cavity opening at the rear of the needle base 5, and the rear part of the elastic support clip 6 is in the shape of a disc and is connected to the needle cylinder 1 The annular anti-recession groove 105 in the back cavity 103 of the neck is matched.

The needle tip at the front end of the needle tube 7 passes through the eccentric hole 201 of the eccentric baffle 2 and the needle through hole 107 of the syringe 1 and is exposed, and the rear end of the needle tube 7 is fixed in the needle fixing hole of the needle holder 5.

The sealing ring 8 is installed in the sealing ring installation groove of the needle seat 5, and the sealing ring 8 is in a sealing fit with the inner wall of the neck rear cavity 103 of the needle cylinder 1.

Referring to Figure 1, when the pull-back syringe is ready to be used or filled with injection, the front part of the core rod 3 and the piston 4 are in the rear end of the barrel 1, and the elastic barb 304 of the core rod 3 is in the barrel 1. Before the annular stop step 106.

Referring to Fig. 6, when using a pull-back syringe for injection, push the core rod 3 so that the core rod 3 and the piston 4 move forward together to feed the injection solution. When the core rod 3 is pushed to the bottom, the piston 4 abuts the needle seat 5. During the forward movement of the core rod 3, the safety disc 305 of the core rod 3 cooperates with the rear end surface of the syringe 1 to limit the forward movement of the core rod 3 and avoid self-destruction due to excessive pushing. The inverted buckle 301 of the core rod 3 has always been behind the buckle 601 of the elastic support clip 6, and has not crossed the buckle 601 of the elastic support clip 6 forward to form an interlock.

Referring to Figure 7, after the pull-back syringe is finished feeding the injection, first press the fuse 305 of the core rod 3, so that the fuse 305 is stuck in the inner hole of the syringe 1, so that the core rod 3 can be pushed continuously. state. Continue to push the core rod 3, the core rod 3 continues to move forward, the elastic support body 302 of the core rod 3 enters the inner hole of the piston 4 from the rear end of the piston 4, and the undercut 301 of the core rod 3 forwards over the elastic support clip 6 The buckle 601 forms an interlock, and the pull-back syringe enters a preliminary state of self-destruction.

Referring to Figure 8, after the pull-back syringe enters the initial state of self-destruction, pull the core rod 3 back. Because the front end of the core rod 3 and the elastic support clip 6 form an interlock, the elastic support body 302 of the core rod 3 supports the piston 4. The elastic support clip 6, the needle seat 5, the needle tube 7, and the piston 4 move back together with the core rod 3. When the needle tip of the needle tube 7 exits the eccentric hole 201 of the eccentric baffle 2, the eccentric baffle 2 that loses the support of the needle tube 7 will move freely along the radial plane in the front cavity 102 of the neck of the needle tube 1 until it reaches a balanced state. The eccentric baffle 2 in a balanced state is in balance with the inner wall of the front neck cavity 102 of the barrel 1 through the fulcrum on the outer contour. The solid surface of the eccentric baffle 2 blocks the needle through hole 107 of the barrel 1, effectively preventing the The needle tube 7 moving in the axial direction passes through the eccentric baffle 2 forward, and the blind hole 202 on the peripheral side of the eccentric hole 201 evades the needle tip of the needle tube 7 and is introduced into the eccentric hole 201 through a rounded corner. When the elastic barb 304 of the core rod 3 passes over the annular stop step 106 of the syringe 1, the annular stop step 106 of the syringe 1 is caught between the stop piece 303 of the core rod 3 and the elastic barb 304, and the syringe 1 The annular stop step 106 cooperates with the stop piece 303 of the core rod 3 to restrict the core rod 3 from continuing to move backward, and the elastic barb 304 of the needle cylinder 1 cooperates with the stop piece 303 of the core rod 3 to restrict the core rod 3 from moving forward. After that, break the core rod 3 from the gap of the core rod 3. At this time, the front of the core rod 3, the elastic support clip 6, the needle seat 5, the needle tube 7, and the piston 4 remain in the needle tube 1, and the needle tube 7 is Completely shielded, the pull-back syringe is in a completely self-destructive state.

In addition, the number of the eccentric baffle 2 in this embodiment is three, and the number of the eccentric baffle 2 can be more or less, as long as it can block the needle through hole 107 of the syringe 1. The three eccentric baffles 2 have two postures in the equilibrium state in the front cavity 102 of the neck of the syringe 1, see FIG. 9 and FIG. 10. In a posture of the three eccentric baffles 2 shown in FIG. 9 in a balanced state, the center distance between the eccentric hole 201 of the eccentric baffle 2 and the needle through hole 107 of the needle cylinder 1 is L1, and the movement trajectory of the eccentric hole 201 is A circle with a radius of R1 (R1=L1); the three eccentric baffles 2 shown in Figure 10 are in another posture in a balanced state, the eccentric hole 201 of the eccentric baffle 2 and the needle through hole 107 of the syringe 1 The center distance is L2, and the movement track of the eccentric hole 201 is a circle with a radius of R2 (R2=L2). Among them, the diameter of the eccentric hole 201 of the eccentric baffle 2 is d, and the diameter of the needle through hole 107 of the syringe 1 is D, L1>(D+d)/2, L2>(D+d)/2, L1( R1) and L2(R2) can be the same or different. In this way, the eccentric hole 201 of the eccentric baffle 2 will always maintain a state of non-intersecting and non-overlapping with the needle through hole 107 of the syringe 1 in a balanced state, and the edge of the eccentric hole 201 can shield the needle hole of the needle tube 7.

It should be pointed out that for the fully explained present invention, there can also be various conversion and modified embodiments, which are not limited to the specific examples of the above-mentioned embodiments. The above-mentioned embodiments are merely illustrative of the present invention, rather than limiting the present invention. In short, the protection scope of the present invention should include those alterations or substitutions and modifications that are obvious to those of ordinary skill in the art.

Claims

A pull-back syringe with a shielding needle eccentric baffle, comprising a syringe, a core rod, a piston, a needle seat, an elastic support clamp, and a needle tube, and is characterized in that:

An inner baffle with a central opening is provided in the neck at the front end of the syringe, and the inner baffle divides the inner cavity of the neck of the syringe into a front neck cavity and a back neck cavity. The front neck cavity is connected to the neck cavity. The needle through hole at the front end of the needle cylinder is connected, and the needle seat is installed in the back cavity of the cylinder neck; the inner wall of the back part of the needle cylinder is provided with an annular stop step protruding in the circumferential direction, and the outer wall of the front part of the core rod is provided There are baffles and elastic barbs arranged front and back, and the baffles and elastic barbs are matched with the annular stop step of the needle cylinder;

It also includes an eccentric baffle, the eccentric baffle is installed in the front cavity of the neck of the barrel, the eccentric baffle is arranged along the radial plane, and is axially limited by the internal structure of the front cavity of the neck and the inner baffle, eccentric The number of the baffle is more than one, the eccentric baffle is provided with an eccentric hole, the rear end of the eccentric baffle is provided with a plurality of blind holes arranged on the periphery of the eccentric hole in the circumferential direction, and the outer contour of the eccentric baffle is provided with two The above fulcrum; the rear end of the needle tube is fixed on the needle seat, and the needle tip at the front end of the needle tube passes through the eccentric hole of the eccentric baffle and the needle through hole of the needle tube is exposed;

When the core rod pulls back the needle tip of the needle tube and exits the eccentric hole of the eccentric baffle, the eccentric baffle that loses the support of the needle tube will move freely along the radial surface in the front cavity of the neck of the needle tube until it reaches a balanced state. The lower eccentric baffle keeps balance through contact with the inner wall of the front cavity of the barrel neck of the barrel through the fulcrum on the outer contour, the solid surface of the eccentric baffle blocks the needle through hole of the barrel, and the blind hole around the eccentric hole avoids the needle tip of the needle to enter In the eccentric hole;

When the elastic barb of the pulled-back core rod crosses the annular stop step of the needle cylinder, the annular stop step of the needle cylinder is caught between the baffle piece of the core rod and the elastic barb to restrict the axial movement of the core rod.
The pull-back syringe with a shielding needle eccentric baffle according to claim 1, wherein the inner wall of the back cavity of the neck of the syringe barrel is provided with a protruding tooth sleeve in front, and the needle seat The outer wall of the middle part is provided with a tooth hub matched with the tooth sleeve of the needle cylinder.
The pull-back syringe with a shielding needle eccentric baffle according to claim 1, wherein the inner wall of the back cavity of the barrel neck of the syringe barrel is provided with an annular stop groove recessed in the circumferential direction at the back, so The rear part of the elastic supporting clip is in the shape of a disc and is matched with the annular stop groove of the needle cylinder.
The pull-back syringe with a shielding needle eccentric stopper according to claim 1, wherein the outer wall of the front end of the core rod is provided with an inverted buckle, and the front part of the elastic support clip is fitted by a snap-fit Installed in the cavity of the rear part of the needle seat, the front part of the elastic supporting clip is in a hollow cylindrical shape, and the inner wall of the front part is provided with a buckle matched with the inverted buckle of the core rod.
The pull-back syringe with a shielding needle eccentric baffle according to claim 1, wherein the rear outer wall of the needle seat is provided with a sealing ring installation groove recessed in the circumferential direction, and the sealing ring is installed A sealing ring is installed in the groove.
The pull-back syringe with a shielding needle eccentric baffle according to claim 1, wherein the front outer wall of the core rod is provided with an elastic support body, and the elastic support body is connected to the rear end surface and the inner wall of the piston Cooperate.
The pull-back syringe with a shielding needle eccentric baffle according to claim 1, wherein the rear outer wall of the core rod is provided with a safety sheet, and the safety sheet is opposite to the rear end surface and the inner wall of the syringe barrel. Cooperate.
The pull-back syringe with a shielding needle eccentric baffle according to claim 1, wherein the eccentric hole of the eccentric baffle is provided with rounded corners along the edge.